Very restrictive set of firewall rules script is a sample firewall for ip_tables, the tool for doing firewalling and masquerading under the 2.3.x/2.4.x series of kernels.

Be warned, this is a very restrictive set of firewall rules (and they should be, for proper security). Anything that you do not _specifically_ allow is logged and dropped into /dev/null, so if you're wondering why something isn't working, check /var/log/messages.

This is about as close as you get to a 'secure' firewall. It's nasty, it's harsh, and it will make your machine nearly invisible to the rest of the internet world. Have fun.

To run this script you must 'chmod 700 iptables-script' and then execute it. To stop it from running, run 'iptables -F'